No, I just understand game mechanics well enough that I can tell you that there was no greater depth or dynamics at 75 in the majority of instances.And I understand that you don't see Abyssea as a problem, but some of us do. Just because you don't give a $#!% about DEPTH and DYNAMICS, doesn't mean that others share similar thoughts.
The only real difference nowadays is that you require less people on a fight-to-fight basis. Needing bodies doesn't add any depth. If SE added an NM tomorrow which was just a standard crab mob but unless you had 18 people it wouldn't take any damage, you wouldn't call it a fight with a great amount of depth, I hope.
Dynamis Lord: zerg
Proto-Omega: absolute joke.
Proto-Ultima: standard tank affair, make sure your tank(s) have an MDT setup.
Genbu: lol.
Seiryu: standard tank affair or RDM it to death.
Suzaku: standard tank affair or RDM it to death. Eat or kite 2hr.
Byakko: standard tank affair or RDM it to death.
Kirin: zerg or kite while you kill adds, then kill it.
Almost all Jailers are more of the same. Love/Prudence are somewhat different.
Faf/Nid/Behe/KB/Ada/Aspid are all and were all easy and easily killable lowman, though you wouldn't see this because of the claim system. Not much depth in these either.
Wyrms: tank on ground, equip mdt set in air. Kite away adds.
Vrtra has depth if you don't zerg it.
I'm not seeing the great amount of depth here. That's not to say that Abyssea fights are the most profound monster battles ever created, but I think you have a serious case of the rose-tinted glasses.